This invention relates to leveling devices or "shoes" for supporting heavy equipment such as machine tools or the like in which a horizontally slidable wedge provides for adjustment of the vertical spacing between an upper and lower support plate.
Devices of this type are in widespread use and shown, for example, in Patent DE-PS 1,297,409. Such devices consist of several parts which are stacked on each other to form a unit. The contact area between wedge and headplate as well as between wedge and footplate, is maintained in alignment by sliding keys in keyway slots. The keys serve also to prevent relative the sideward between the parts.
The machines and plant equipment which are mounted on such devices produce, during operation, various types of vibrations which are transferred to the mount. In order to absorb these vibrations it has been proposed to equip the area of the foot and headplate with vibration dampening material. A mount equipped with this material cannot give satisfactory results since it not only serves as an elastic bearing but also precludes precision levelling of the machines resting on it.
The present invention ensures that the dangerous resonance zone vibrations can be controlled. This result is attained by changing the natural frequency of the mounts. In the present invention consideration has been given to the natural frequency of the parts. Since all these parts are manufactured with certain tolerances resulting from the production process and are loosely connected to each other whereby the moving parts in particular have certain clearances, this construction gives a different natural frequency to each part. When operating the machine which is lying on the mount the natural frequency of the single parts is often approached or exceeded meaning that certain parts of the mount are reaching the resonance zone. This is a disadvantage for the moving and guiding areas of the various parts as well as for the precision levelling for the machine supported by the mount. The object of the present invention is to manufacture a mount as described with which these disadvantages can be eliminated. This is achieved in the new leveling mount which features pre-tensioned spring elements between the various mount parts to ensure a spring elastic constant compactness and vibration resonance control.